An openingopeningOpeningOpeningOpeningopening operation is defined as an erosion followed
by a Minkowski addition. By applying openingopeningOpeningOpeningOpeningopening to a
region, larger structures remain mostly intact, while small
structures like lines or points are eliminated. In contrast, a
closingclosingClosingClosingClosingclosing operation results in small gaps being retained
or filled up (see closingclosingClosingClosingClosingclosing).
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
Example (C)
/* simulation of opening */
my_opening(Hobject In, Hobject StructElement, Hobject *Out)
{
Hobject H;
erosion1(In,StructElement,&H,1);
minkowski_add1(H,StructElement,Out,1);
}
/* Large regions in an aerial picture (beech trees or meadows): */
read_image(&Image,"forest_road");
threshold(Image,&Light,160.0,255.0);
gen_circle(&StructElement,100.0,100.0,10.0);
/* selecting the large regions */
opening(Light,StructElement,&Large);
/* Selecting of edges with certain orientation: */
read_image(&Image,"fabrik");
sobel_amp(Image,&Sobel,"sum_abs",3);
threshold(Sobel,Edges,30.0,255.0);
gen_rectangle2(&StructElement,100.0,100.0,3.07819,20.0,1.0);
opening(Edges,StructElement,&Direction);
Example (HDevelop)
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
Example (HDevelop)
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
Example (HDevelop)
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
Complexity
Let F1 be the area of the input region, and F2 be the area of
the structuring element. Then the runtime complexity for one region
is:
Result
openingopeningOpeningOpeningOpeningopening returns 2 (
H_MSG_TRUE)
if all parameters are correct.
The behavior in case of empty or no input region can be set via: